Method and process for creating high-performance coax sockets

Abstract

The present invention provides a novel method of constructing a coax spring-pin socket that furnishes better performance and is easier to manufacture in volume using common dielectrics and copper plating. This is accomplished by, in application, a lamination of PCB dielectric layers. This dielectric block is then drilled, plated, etched, and drilled in steps for the construction of a coaxial structure for the signal pins, and a ground structure for ground pins. This design process that can be quickly adjusted and customized for each design.

The invention claimed is: 
     
       1. A method of creating high-performance coaxial (coax) sockets in printed circuit boards (PCB), the method comprising steps of:
 a. laminating a first printed circuit board (PCB), said PCB having a core and PCB pre-preg laminates that are laminated together forming a single PCB sheet of material for a coaxial body; 
 b. machining said single PCB sheet of material to a target thickness in a range from 0.030 inches and 0.150 inches; 
 c. drilling holes in said single PCB sheet of material for a primary hole for a coaxial socket and vent holes; 
 d. electroplating said primary hole with conductive material; 
 e. removing selected conductive material from a surface of said single PCB sheet of material to provide a large enough gap between a return path and a coax pin to be retained in said coaxial socket, said pin having a coax pin plunger, 
 wherein said coax pin is a power pin isolated from a ground plane and having adjacent vias, said coax pin configured for low impedance or configured to provide a desired current carrying capacity, wherein the coax pin is further characterized as having an impedance in the range of 0.5 to 10 ohms and a current carrying capacity up to 10 amps; 
 f. drilling a hole in said single PCB sheet of material for said coax pin plunger to go through; and 
 repeating steps a-f for a second printed circuit board (PCB) to form a second PCB sheet, and 
 assembling said first and second PCB sheets together to form a coaxial board, and placing a spring pin in said core of said coaxial board to be retained in said core. 
 
     
     
       2. The method according to  claim 1  wherein said electroplating conductive material is copper. 
     
     
       3. The method according to  claim 1 , wherein in creating each of said coaxial socket bodies, a layer of electrical conductive material is added or left on a top or bottom surface of each said body for electroplating subsequently. 
     
     
       4. The method according to  claim 1 , wherein said target thickness will vary within said range depending on said spring pin type and a device under test (DUT) requirements. 
     
     
       5. The method according to  claim 1 , further including a generic pin hole and wherein said generic pin hole does not require plating in the hole for the generic pin, or generic pin, respectively and a two-step hole is drilled for placement of said generic pin including a larger hole and a smaller hole, where said smaller hole that allows said plunger of said generic pin to pass there-through said smaller hole and block a barrel or circumference of said generic pin from passing through said smaller hole capturing said generic pin in said coax socket. 
     
     
       6. The method according to  claim 1 , further including a ground pin and a two-step hole is drilled for placement of said ground pin including a larger hole and a smaller hole, said hole being plated with electrically conductive material including gold, copper or silver material, and where said smaller hole that allows said plunger of said ground pin to pass there-through said smaller hole and block a barrel or circumference of said ground pin from passing through said smaller hole capturing said ground pin in said coax socket, said plating on a surface of said ground hole providing electrical connection with said spring pin for connection with said ground pin over multiple compressions. 
     
     
       7. The method according to  claim 6 , wherein there is at least one adjacent ground pin for each spring pin where said ground pin provides a return path for a coax transmission line. 
     
     
       8. The method according to  claim 1 , further including:
 etching said conductive material around said power pin leaving a path between additional vias and a spring pin hole; 
 drilling a plurality of two-step vias; and 
 plating said vias with electrically conductive material including copper, gold or silver. 
 
     
     
       9. The method according to  claim 1 , wherein a dielectric guide frame is added to either a top or a bottom socket body to hold all pins in a vertical orientation. 
     
     
       10. The method according to  claim 9 , wherein said dielectric guide frame electrically isolates said socket body from said PCB. 
     
     
       11. The method according to  claim 10 , further including a solder ball nest added subsequently to said dielectric guide frame, wherein said solder ball nest serves to align a device under test's (DUT's) solder balls with the spring pins. 
     
     
       12. The method according to  claim 9 , further including screws to assemble all aligned pieces together as an assembly.